Canada

John Oliver has a episode on this and it changed my mind. Sure at the top level there has to be conversations about this but for kids and non pros which lets be honest is the vast majority of people playing sports, just let people play.

Agreed; it's not worth the rhetoric and actions. And while there's definitely merit in assessing trans athletes to try and keep things as fair as possible (though they never stopped Phelps from competing, so "fair" is kind of a joke), it's far more complex than a simple "there was testosterone so they have an advantage!"

For the "nonathletic" groups - think community-level sport - based on what data is available, there is effectively no statistical difference between cis and trans women's physical performance after 2+ years on hormone therapy.

When it comes to elite athletes, trans women outperformed cis women in Fat-free mass index, Absolute hand grip strength, and Absolute Vo2Max, but under-performed in Relative VO2Max to mass, Ratio of expiratory volume to vital lung capacity, and Absolute countermovement jump (lower body power). The lower Relative VO2Max, and Expiratory volume can lead to disadvantages in terms of speed, recovery and endurance.

While hand grip strength is considered an indicator of overall muscle strength, to quote the first article linked:

The correlations between hand grip strength and individual sports are reviewed comprehensively in Cronin et al. Though maximum hand grip strength has a strong relationship with maximum upper or body strength in some movement patterns such as in powerlifting strength, there are weaker relationships with other movement patterns. There is evidence that hand grip strength is a poor correlate of knee flexion or extension strength and is far more reliable as a marker of physical function if used together with lower limb strength. Hand grip strength is more relevant for some physical performance activities such as rotational movements that transfer force and torque to the hand (ie, ball throwing), but shows poor correlation to movement patterns that require technical ability, physical capacity, aerobic fitness or tactical ability (ie, tennis stroke placement or cricket fielding performance)

It will require a lot more information before any athletics group would be able to make a truly informed decision, and it's going to have to be sport by sport. Elite athletes are all outliers in their genetic makeup (Phelps, The average height of a WNBA player, etc). We know athletes have different hormone levels depending on the sport they play, but it's chicken vs. egg on whether the hormones or elite performance came first. So trying to decide what is an acceptable advantage re: "pro athlete genetics", vs. an unacceptable advantage re: "transgender genetics" is little more than opinions and politics at this point.

/info dump

Some people assume nefarious individuals would go into ladies change rooms, washrooms, or prisons.